1. Field of the Invention
The present invention relates to a firing range and more particularly the present invention relates to a firing range for use in training of personnel in marksmanship.
2. The Prior Art
At the present time, when personnel are trained in firing a weapon such as a rifle it is common to utilise a static firing range in which the personnel fire their weapons at targets which are remote from the firing point, the position that each round impinges on the target being indicated by further personnel acting as markers who are located adjacent the targets but protected by an earth bank or the like.
This arrangement suffers from the disadvantage that for every trainee marksman there must be a person to act as a marker, and furthermore a rigid target must be utilised which must be repaired after each shooting session so that the point of impact of further rounds on the target can readily be determined.
A further disadvantage of this prior arrangement is that the sport of shooting is not appealing as a spectator sport since spectators cannot readily see how the shooting is progressing.
Yet a further disadvantage of the prior proposed arrangement is that personnel training the trainee marksman find it difficult to monitor the progress of a large number of trainee marksman and have to inspect the targets by means of a telescope or binoculars in order to assess how a trainee marksman is performing. This procedure is time-consuming and inconvenient.
Various attempts have been made to overcome these disadvantages.
Several proposals have been made in which transducers or similar shock wave detectors are connected directly to a rigid target or a rigid member located behind the target, the detectors being adapted to detect shock waves or vibrations generated in the target or member by the impact of a bullet on the target. The signals from the detectors are fed to a calculating device which calculates the position of the bullet or other projectile, and which causes that position to be displayed or stored. Specifications that disclose the systems of this general type are U.S. Pat. No. 2,973,964 (Zito) and U.S. Pat. No. 3,678,495 (Gilbert). Both these particular systems suffer from the disadvantage that a rigid target or member must be used, and the rigid target or member must be replaced after a certain period of use, since otherwise the target or member will be perforated by bullets fired at the target and then the target or member will not satisfactorily transmit the shock waves or vibrations generated when a bullet impinges on the target. Also, if a rigid target is used, with very accurate marksmen a hole will soon be generated in the region of the "bull" of the target, this hole having a diameter greater than the diameter of the bullets being fired at the target. Thus after a period of time a bullet may pass through this hole without generating shock waves, and a shot that should be recorded as a "bull" will be recorded as a "miss". Furthermore since the transducers are spaced around the periphery of the target or member the transducers may themselves be hit by bullets fired at the target, and thus the transducers may be damaged. Thus these systems suffer from the disadvantage of expense in that both the targets or rigid members and the transducers will have to be replaced at frequent intervals.
Various alternative proposals have been made in which transducers or the like are utilised to detect an air-carried shock wave generated by a bullet or projectile which travels at a speed faster than the speed of sound in air. Such a projectile can be called a supersonic projectile. One very simple proposal of this type is disclosed in U.S. Pat. No. 2,783,047 (Faxen) in which a single shock wave sensitive device is operated to generate a signal in response to a shock wave generated by a supersonic projectile such as bullet and impinging on the device. The shock wave sensitive device is mounted in a target area zone bounded by a wall so that the device will be responsive to shock wave impulses produced by bullets entering the target area but not those produced by projectiles which pass outside the target area. It will be appreciated, therefore, that this particular arrangement will only be able to distinguish between a "hit" and a "miss" and will not be able to provide any accurate information concerning the precise position at which a bullet impinged upon the target area. A further proposal in which airborne acoustic shock waves produced by a supersonic projectile such as a bullet are utilised is described in U.S. Pat. No. 3,778,059 (Rohrbaugh) and in this Specification two metal rods are located respectively adjacent the base and one side edge of the target, there being acoustic transducers attached to the ends of the rods. When a bullet is fired at the target the shock wave generated by the bullet will impinge on the rods, and a resultant acoustic wave generated by the rods will be transmitted to the transducers which subsequently produce an electric signal. The resultant signals are fed to a timing and calculating device which calculates the position of the trajectory of the bullet and permits the position at which the bullet hits the target to be displayed on a device such as a cathode ray tube.
A further proposed arrangement is described in U.S. Pat. No. 3,489,413 (Groder) and this Specification discloses the use of bi-directional transducers each adapted to detect whether a shock wave generated by a supersonic projectile and impinging on the transducer originates from the left or right of the central axis of the transducer. The specification describes an arrangement in which a plurality of transducers is arranged in a row adjacent the base of the target, and a further plurality of transducers is arranged in a column adjacent the side of the target. In view of the nature of the system it is only possible to determine which broad area of the target was impinged upon by any particular bullet since it will only be possible to determine the position of the bullet by reference to the two transducers at the base of the target between which the bullet passed and the corresponding two transducers at the side of the target. Thus the system only has very limited accuracy and furthermore the transducers provided at the side of the target are susceptible to damage by inaccurate firing.
A further prior proposal is disclosed in U.S. Pat. No. 2,925,582 (Mattei) and this Specification discloses the use of four transducers spaced around the periphery of a target area, signals derived by the four transducers when a bullet is fired at the target being fed to an appropriate calculating and display device adapted to calculate and display the position of the bullet. The calculating device initially determines the duration of the shock wave detected by each transducer, since the duration of the shock wave increases with increasing distance from the origin of the shock waves. Signals representative of the durations of the shock wave control the beam scanning circuits of a display device. This prior proposed arrangement suffers from the disadvantage that at least three of the transducers are exposed to fire from the marksmen and are thus susceptible to damage. Furthermore, the levels of accuracy obtainable with the system described in this U.S. Specification are not very high.
It will be appreciated that the prior art discussed above discloses the general use of transducers to detect shock waves present in a rigid target or to detect airborne shock waves generated by a projectile such as a bullet, but all the prior proposed arrangements suffer from either the disadvantage that the arrangement does not provide an accurate indication of the precise position of the bullet, or the disadvantage that the transducers are in a position in which they may be damaged by bullets hitting the transducers. Furthermore, some of the prior proposals suffer from the disadvantage that rigid targets must be provided which must be replaced regularly to ensure that shock waves are transmitted satisfactorily through the rigid targets.